Full-chain efficiency screening of CCU pathways: Evidence from 60 routes in China

Carbon capture and utilization (CCU) is regarded as a critical pathway for the low-carbon transition of the industrial sector. However, due to the substantial technological heterogeneity and complex cross-stage coupling inherent in CCU systems, the prevailing focus of existing studies on individual stages fails to capture comprehensive pathway-level performance. To address this gap, this study introduces a double-frontier network DEA framework into full-chain CCU evaluation to support pathway characterization and screening, simultaneously assessing optimistic efficiency (representing pathway performance potential under optimistic scenarios) and pessimistic efficiency (reflecting robustness under unfavorable conditions). Furthermore, a three-stage network structure comprising 8 capture technologies, 2 transport modes, and 11 utilization technologies is constructed, resulting in 60 feasible CCU pathways. The network DEA model incorporates investment cost, energy consumption, and technological maturity as inputs, while output value and abatement potential are treated as desirable outputs and CO₂ leakage as an undesirable output. Results show that overall efficiency ranges from 0.14 to 0.46 (mean = 0.24; median = 0.25), indicating a relatively low-to-moderate level of multidimensional system performance, and high-efficiency pathways are mainly concentrated in pipeline transport and mineralization technologies. In addition, 11 robust pathways and 18 opportunity-oriented pathways are identified, providing quantitative evidence for pathway screening and differentiated deployment. Regional comparisons further reveal marked structural reordering of pathway performance across typical regions, with region-specific high-efficiency portfolios reflecting differences in industrial composition, emission intensity, and market conditions.